Fuel Pump: Testing and Inspection
Fuel Pump Circuit Troubleshooting
If you suspect a problem with the fuel pump, check that the fuel pump actually runs; when it is on, you will hear some noise if you listen to the fuel fill port with the fuel fill cap removed. The fuel pump should run for 2 seconds when the ignition switch is turned to ON (II). If the fuel pump does not make noise, check as follows:
1. Turn the ignition switch to LOCK (0).
2. Remove the driver's dashboard lower cover Driver's Dashboard Lower Cover Removal/Installation.
3. Remove PGM-FI main relay 2 (FUEL PUMP) (A) from the driver's under-dash fuse/relay box.
4. Turn the ignition switch to ON (II).
5. Measure the voltage between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 4 and body ground.
Is there battery voltage?
YES -
Go to step 14.
NO -
Go to step 6.
6. Turn the ignition switch to LOCK (0).
7. Remove PGM-FI main relay 1 (A) and the ETCS control relay (B) from the under-hood fuse/relay box.
8. Jump the SCS line with the HDS.
9. Disconnect ECM/PCM connector A (49P).
10. Disconnect engine wire harness connector C101 at the left side of the engine compartment.
11. Disconnect the driver's under-dash fuse/relay box connector F (33P).
12. Connect PGM-FI main relay 1 4P connector terminal No. 2 to body ground with a jumper wire.
13. Check for continuity between driver's under-dash fuse/relay box connector F (33P) terminal No. 31 and body ground.
Is there continuity?
YES -
Replace the driver's under-dash fuse/relay box; USA models Drivers Under-dash Fuse/Relay Box (Drivers MICU) Removal and Installation (USA Models), Canada models Drivers Under-dash Fuse/Relay Box (Drivers MICU) Removal and Installation (Canada Models).�
NO -
- Repair open in the wire between the under-hood fuse/relay box and the driver's under-dash fuse/relay box.�
- If the wire is OK, replace the under-hood fuse/relay box Drivers Under-dash Fuse/Relay Box (Drivers MICU) Removal and Installation (USA Models).�
14. Measure the voltage between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 2 and body ground.
Is there battery voltage?
YES -
Go to step 15.
NO -
- Check the No. 9 FUEL PUMP (20 A) fuse in the driver's under-dash fuse/relay box.�
- If the fuse is OK, replace the driver's under-dash fuse/relay box; USA models Drivers Under-dash Fuse/Relay Box (Drivers MICU) Removal and Installation (USA Models), Canada models Drivers Under-dash Fuse/Relay Box (Drivers MICU) Removal and Installation (Canada Models).�
15. Turn the ignition switch to LOCK (0).
16. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 3 to body ground with a jumper wire.
17. Jump the SCS line with the HDS.
18. Disconnect ECM/PCM connector A (49P).
19. Check for continuity between body ground and ECM/PCM connector terminal A16.
Is there continuity?
YES -
Go to step 20.
NO -
Repair open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the ECM/PCM (A16).�
20. Reinstall PGM-FI main relay 2 (FUEL PUMP).
21. Connect ECM/PCM connector terminal A7 to body ground with a jumper wire.
22. Turn the ignition switch to ON (II).
23. Measure the voltage between ECM/PCM connector terminal A16 and body ground.
Is there battery voltage?
YES -
Go to step 24.
NO -
Replace PGM-FI main relay 2 (FUEL PUMP).�
24. Turn the ignition switch to LOCK (0).
25. Reconnect ECM/PCM connector A (49P).
26. Turn the ignition switch to ON (II), and measure the voltage between driver's under-dash fuse/relay box connector F (33P) terminal No. 22 and body ground within 2 seconds.
Is there battery voltage?
YES -
Update the ECM/PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good ECM/PCM Initial Inspection and Diagnostic Overview, then recheck. If the symptom/indication goes away and the ECM/PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the ECM/PCM was substituted, replace the original ECM/PCM Service and Repair.�
NO -
Go to step 27.
27. Turn the ignition switch to ON (II), and measure the voltage between driver's under-dash fuse/relay box connector F (33P) terminal No. 22 and body ground after 2 seconds.
Is there battery voltage?
YES -
Go to step 28.
NO -
Replace the driver's under-dash fuse/relay box; USA models Drivers Under-dash Fuse/Relay Box (Drivers MICU) Removal and Installation (USA Models), Canada models Drivers Under-dash Fuse/Relay Box (Drivers MICU) Removal and Installation (Canada Models).
28. Turn the ignition switch to LOCK (0).
29. Remove the rear seat cushion Rear Seat Removal/Installation.
30. Remove the access panel from the floor Fuel Tank Unit Removal/Installation.
31. Turn the ignition switch to ON (II), and measure the voltage between fuel tank unit 4P connector terminal No. 2 and body ground within 2 seconds.
Is there battery voltage?
YES -
Go to step 36.
NO -
Go to step 32.
32. Turn the ignition switch to LOCK (0).
33. Remove PGM-FI main relay 2 (FUEL PUMP).
34. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminals No. 1 and No. 2 with a jumper wire.
35. Turn the ignition switch to ON (II), and measure the voltage between fuel tank unit 4P connector terminal No. 2 and body ground.
Is there battery voltage?
YES -
Replace PGM-FI main relay 2(FUEL PUMP).�
NO -
- Repair open in the wire between the driver's under-dash fuse/relay box (D10) and the fuel tank unit 4P connector.�
- If the wire is OK, replace the driver's under-dash fuse/relay box Drivers Under-dash Fuse/Relay Box (Drivers MICU) Removal and Installation (USA Models).�
36. Turn the ignition switch to LOCK (0).
37. Check for continuity between fuel tank unit 4P connector terminal No. 4 and body ground.
Is there continuity?
YES -
Replace the fuel pump Fuel Pump/Fuel Gauge Sending Unit Replacement.�
NO -
Repair open in the wire between the fuel tank unit 4P connector and G603; 4-door Harness Locations, 2-door Harness Locations.�